Hand-brake booster



4 1927. 1,612,994 Jan f s. J. sTRllD HAND BRAKE oosTEn Filed May 2. 1925 2 sheets-sheet 1 S. J. STRID HAND BRAKE BOOSTER Jan. 4 1927.

Filed May 2. 1925 2 Sheets-Sheet 2 Patented J an.r 4, 1927.

UNITED STATES.

PATENT OFFICE.

SVEN JUL'IUs srnID, Lor cmoaeo, ILLINOIS, AssIGNon *ro FRED .MA'rnEWs on CHICAGO,

ILLINOIS.

l HAND-BRAKE BOOSTER.

AppIication led May 2,

My present invention relates toV gearing and more'particularly to a geared structure for operating the brakes on railway cars, although the structure may be used for other purposes or wherever its principles may be found advantageous.v Y f In freight cars and similar vehicles where hand brakes are used it is well known that there is usually slack inthe chains, rods, and levers that must be taken up before the brake-shoes are brought into contact with thewwheels. To take up this slack as Well as to apply the initial pressure of the shoes against the wheels requires very little elort as compared to the power necessary to tightenvthe shoes suliciently to render their brakingaction'effective upon the moving, wheels. Usually itlhas been the practice for the brakeman to give the wheel on the brakemast a spin to take up lthe slack and thereafter to pull on the wheel with his greatest effort to set the brakes.

AMy geared structure is especially designed to be applied to the brake mechanism of a railway c'ar and is so constructed that only av slight rotative movement of the brakewheel is necessary to take up the slack and thereafter the gear ratio changes so that with the same or slightly less force than is usually required a greater pressure is exerted bythe shoes kagainst the wheels.

The device is compact and simple in construction, is made from few parts, and is novel and dependable in operation.

I prefer to` carry outiny invention and accomplish its diversv objects in substantially the manner hereinafter fully described and as more particularly pointed out in the claims, reference being made to the accompanying drawings that form a part of this specification.

- In the drawings v Fig. 1 is a top plan of my invention' showinit applied toa railway car brake." s

ig. 2 is ia side elevation of the structure shown-inFig.' 1.

Fig. 3 1s a transverse section on line 3.3

of Fig. 2 and drawn to a larger scale.

Fig. 4 is a schematic top plan of my device detached and drawn to anv enlarged scale. In this view the parts are illustrated.

:in their relative positions at the beginning of their movement.

Fig. 5 is a view similar to Fig. 4 showing 1 the relative positions of the parts when the 1925. serialfmr. 27.588. y

greatest power is being applied to the brakeshoes. y 3

Fig. 6 is a faceview of one end of the reciprocable rack. l

In the drawings, which illustrate a typical or preferred embodiment of my invention, I have employed the same reference characters to designate corresponding parts wherever the same1 appear throughout the several views.

Secured to one of the longitudinal sills 10 of the car underframe is a carrier for the gear device in the form of a U-shaped casting that is set sidewise (Fig. 2) and is supported by horizontal straps l1 and inclined bracing straps 12that are bolted or otherwise .secured at their end to the sill. rIhe upper member ofthe U-shaped casting isa substantially flat rectangular plate/13 the outer edge of which is provided with a depending flange 14 of a J-shape section and spaced from this flange and above 'the hook end of the J is a rib 15 that alines vertically therewith so that there is provided a guideway or guidechannel 16 for the reciprocal rack which willhereinaftenbe described in detail. The connecting member 17 of the U-shaped casting is preferabl. vertically disposed and extends downwardly from the forward edge of the plate 13 and from the lower edge of this memberthe other horizontal member of the U-shaped casting extends rearwardly under the plate in the form of a tapered bracket y18 that terminates centrally of the plate 13 where it is provided with a bearing-.boss for the spindle 19 of the v pinion that coacts with the rack above mentioned; At the rear outer corner of the plate 13 there is a tubular extension 20 the interior of which is shaped similar to the guideway or channel to receive the rack, and the outer edge of this extension is provided `with a conc-ave seat 21. l

Rotatably mounted on the spindle 19'V is the gear member 22' of substantlally a scroll 'outline and provided with the peripheral teeth,` while the hub 2 3 which is elongated below the member l22 has a Winding drum 24 secured' to itvto which the adjacent end of the chain is anchored. 9

The teeth 26 on the edge of the gear member 22 between the points A and B (Figs.

4 and 5) are arranged concentric to the,`

axis of the member and the axis of rotation thereof thus providing a segmental gear.

and the teeth 27 between the points B and C (Figs. 4 and 5) arey arranged in a convolute I and are eccentric to said axis, so that the whole member may be said to be of the scroll gear type.

The gear member thatcoacts with the one just described comprises a reciprocablerack in -the form of an elon atedl bar 28 having teeth upon 011e edge an having a Tshaped flange29 extending along its edge opposite the teeth that fits the guide channel 16 heretofore allude-d to. The teeth 30 on the rack between the outer'r'e'ar end D thereof and y the point lil are parallel "with the o posite 27are engaged with end F of the curved set of rack teeth 31 and when the rack is moved tothe right in the direction of the arrow Y(llig. 4) the maximum ratio between the gear members is etfective and the gear 22 is rotated rapidly to take up all slack and lost motion in the chain levers, rods and the like. This maximum ratio gradually reduces during the longitudinal ,movement of the rackin the direction of the arrow until the concentric set of teeth 26 between the pivots A-B on the scroll gear are engaged "with the longitudinal parallelset 30 of therackl j between vthe points D-Ethereof, which reduces the ratio to a minimum, but the force that is then being applied to thewinding drum 24 has been greatly Aincreased over what itwas when the gear was driven faster wir bythe rack during initial movement. l

The forward end of the rack element is provided with a bifurcation 32 between the arms of which the adjacent end of the pull rod 33 is pivotally connected by a bolt 34, and back of thebiurcation the web/ of the rack member is cut down as at 35 to rovide a recess into which the wide edge of t e gear member 22 may be positioned as will be understood from the detail in Fig. 4. The opposite end of the rack bar is reduced as at 36 and is threaded to receive cup-washer 37 that is held in terposed between the washer 37 and the concave seat 21 of the casting extension 'is a coiled ex ansion spring 39 that's'urrounds the straig t portion of the rack that projects rearwardly through the tubular extension 20 so that when the pull has been released on bar 33, the spring 39 will automatically rea flanged' or' place by a nut 38 screwed yonto the reduced end 36, and in`` initial position as designated in Fig. 4. The

forward Aend of the pull rod is connected in any manner to the brake mast at the end sill of the car and the rear end of chain 25 is suitably connected to the rocking brake lever 40 at the end of the latter nearest the air-brake cylinder 41, but/it will be understood that other methods of mounting the same may be devised to suit any particular installation.

It is obvious that numerous changes or modiications of the structure herein shown may be made without departing from the principles involved, and l desire it understood that the same are fully contemplated as coming within the scope of the appended claims.

f`What I claim is 1. A hand-brake booster comprising a ranged to constantly mesh with the teeth of said gear, one end of said rack connected with said pull-rod and the opposite end being extended beyond said guideway, and a spring one end of which is engaged with the extended portion of said rack and the opposite 'end is engaged with a portion of ,said carrier, ywhereby to automatically return said glements to normal positions. Y

2. A handbrake booster comprising a brake pull-rod, a carrier, a driven scroll lgearv rotatably mounted therein, a guideway on 'saidf carrier, a driving-'rack reclprocable in said guideway the teeth. of which are arranged tojconstantly mesh with the teeth of said gear, one vend of said rack connected with said pull-rod and the opposite end being extended beyond said guideway, and

a coiled spring surrounding ther extendedend of said rack and one end of which is engaged with the extended portion of said rack and the opposite end is engaged with a portion of said carrier whereby to automatically return said elements to normal posi-,

tions.

3. A khand-brake booster 'comprislng a brake pull-rod,` a carrier of substantially Ussh'ape, a driven gear rotatably mountedl between opposite'members of said carrier, al

guideway extending laterally from one of the members of the .carrier, a driving rack I reciprocable in said guide in mesh with ksaid gear, said rack projecting at one end beyond the vguideway-and at its opposite end connected with saidpull-rod, an abutment upon the vouter end of said rack, and-a coiled s ring surroundlng saldrrack between sald a utment and the adjacent end of the guidee way, whe'reby the rack,pullrod and-gear l are automatically returned to normal posl# tion after each movement opposite to the tension of said sprlng.

andconsisting of a rack` having a terminal gear and engageable with toothed portion curved away from the plane ca a driven gear member of its main portion,

gear of concentric consisting of a segmental outline engageable with the axisl of the segmenta inwardly towards the curved porljects, an

portion of the driving member for automatil the mainv portionV of the rack and an eccentric gear extending tion of the rack, a guide structure through rtion of the driving member p rowhich a means connected to the projectmg l1 returning the gear members and said pul -rod to normal positions. of Cook,

Signed at Chicago, inthe county and State of I11ino1s,.this 27th day of April,

.SVEN JULIUS s'rnn). 

